JP2022118557A - Unit and image forming apparatus - Google Patents

Abstract

To provide a unit that forms a lustrous image having a lustrous feeling formed with a photoluminescent toner.SOLUTION: A unit comprises: a developing device that stores a developer having a photoluminescent toner including a photoluminescent pigment and develops an electrostatic charge image formed on a surface of an image holding body with the developer as a toner image; and a fixing device that has a fixing belt, a first roll and a second roll arranged inside the fixing belt and supporting the fixing belt while applying tensile force to the fixing belt, and a pressure roll sandwiching the fixing belt with the first roll to form a nip part, and has a fixing temperature of 130°C or more and 230°C or less.SELECTED DRAWING: Figure 3

Description

The present invention relates to a unit and an image forming apparatus.

In an electrophotographic image forming apparatus (copier, facsimile machine, printer, etc.), a toner image formed on the surface of an image carrier is transferred to the surface of a recording medium and fixed on the recording medium to form an image. be done.

2. Description of the Related Art In recent years, the use of glitter toners containing glitter pigments has been studied for the purpose of forming images having shine such as metallic luster.

For example, Patent Literature 1 discloses that "a bright pigment, an organic pigment, a binder resin, a release agent, and an external additive are contained, and the toluene-insoluble matter other than the bright pigment and the external additive is 8% by mass. Brilliant toner containing at least 40% by mass.” is disclosed.

JP 2017-062413 A

The glitter of the image by the glitter toner is expressed by parallelization of the glitter pigment on the surface of the recording medium when the toner image is fixed on the recording medium.
However, the fixing belt, the first and second rolls that are arranged inside the fixing belt and support the fixing belt while applying tension to it, and the pressure roll that sandwiches the fixing belt together with the first roll to form a nip portion. and (hereinafter also referred to as a “specific fixing device”) to form a glitter image with a glitter toner, the feeling of glitter may be reduced.

To form a glitter image with a high glitter feeling by the glitter toner in a unit provided with a developing device containing a glitter toner and a specific fixing device, as compared with a case where the fixing temperature of the fixing device is less than 130°C. to provide the unit.

Means for solving the above problems includes the following aspects.
<1> a developing device containing a developer having a bright toner containing a flat bright pigment, and developing an electrostatic charge image formed on the surface of an image carrier by the developer as a toner image;
A fixing device for fixing a toner image on a surface of a recording medium, comprising: a fixing belt; first and second rolls arranged inside the fixing belt to support the fixing belt while applying tension; a fixing device having a pressure roll that sandwiches the fixing belt together with a first roll to form a nip portion, and that has a fixing temperature of 130° C. or more and 230° C. or less;
a unit with
<2> The unit according to <1> or <2>, wherein the nip portion is flat.
<3> The unit according to <1>, wherein the fixing belt is rotationally driven at a linear velocity of 180 mm/sec to 450 mm/sec.
<4> The unit according to any one of <1> to <3>, wherein the surface hardness difference (absolute value) between the first roll and the pressure roll is within 15°.
<5> The unit according to <4>, wherein the first roll has a surface hardness of 35° or more and 45° or less.
<6> The unit according to <4> or <5>, wherein the pressure roll has a surface hardness of 40° or more and 50° or less.
<7> The unit according to any one of <4> to <6>, wherein the pressure at the nip portion is 2.0 kgf/cm ² or more and 7.0 kgf/cm ² or less.
<8> The unit according to any one of <4> to <6>, wherein the pressure at the nip portion is 4.0 kgf/cm ² or more and 7.0 kgf/cm ² or less.
<9> Any one of <4> to <8>, wherein the outer diameter ratio between the first roll and the pressure roll (first roll/pressure roll) is 0.9 or more and 1.3 or less unit described in .
<10> The unit according to any one of <1> to <9>, wherein the glitter toner has a viscosity of 100 Pa·s to 1000 Pa·s at 130°C.
<11> The ratio (C/D) of the average maximum thickness C to the average equivalent circle diameter D in the toner particles of the glitter toner is in the range of 0.001 to 0.700 <1> to <10> The unit according to any one of items 10>.
<12> A toner image forming apparatus comprising an image carrier and the developing device of the unit according to any one of <1> to <11>, wherein a toner image is formed on the surface of the image carrier. a device;
a transfer device for transferring the toner image formed on the surface of the image carrier onto the surface of a recording medium;
A fixing device for fixing the toner image onto the surface of the recording medium, the fixing device being selected from the unit according to any one of <1> to <11>;
An image forming apparatus comprising:

According to the invention relating to <1>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Provided is a unit for forming a glitter image with a high glitter feeling by a glitter toner.
According to the invention relating to <2>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Provided is a unit that forms a glitter image with a high glitter feeling by a glitter toner even if the nip portion is flat.
According to the invention relating to <3>, there is provided a unit that forms a glitter image with a high glitter feeling due to glitter toner compared to the case where the fixing belt is rotationally driven at a linear velocity exceeding 450 mm/sec.
According to the invention according to <4>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Provided is a unit that forms a glitter image with a high glitter feeling by a glitter toner even if the difference (absolute value) in surface hardness between the first roll and the pressure roll is within 15°.
According to the invention relating to <5>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Provided is a unit that forms a glitter image with a high glitter feeling by a glitter toner even if the surface hardness of the first roll is 35° or more and 45° or less.
According to the invention according to <6>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Provided is a unit that forms a glitter image with a high glitter feeling by a glitter toner even if the surface hardness of the pressure roll is 40° or more and 50° or less.
According to the invention according to <7> or <8>, in the unit including the developing device containing the glitter toner and the fixing device provided with the specific fixing device, the fixing temperature of the fixing device is less than 130°C. Even if the pressure at the nip portion is 2.0 kgf/cm ² or more and 7.0 kgf/cm ² or less, or 4.0 kgf/cm ² or more and 7.0 kgf/cm ² or less, compared to the case where there is a certain case, the brilliant feeling by the glitter toner is improved. Provided is a unit that forms a bright image with high .
According to the invention according to <9>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., A unit that forms a glitter image with a high glitter feeling by a glitter toner even when the outer diameter ratio between the first roll and the pressure roll (first roll/pressure roll) is 0.9 or more and 1.3 or less. is provided.
According to the invention according to <10>, there is provided a unit that forms a glitter image with a high glitter feeling by the glitter toner compared to the case where the viscosity of the glitter toner at 130° C. is 100 Pa·s or more and more than 1000 Pa·s. be done.
According to the invention according to <11>, in a unit including a developing device containing glitter toner and a fixing device provided with a specific fixing device, compared to the case where the fixing temperature of the fixing device is less than 130° C., Even if the ratio (C/D) of the average maximum thickness C to the average equivalent circle diameter D in the toner particles of the glitter toner is in the range of 0.001 to 0.700, the glitter toner gives a glitter feeling. Provided is a unit that forms a bright image with high .
According to the invention according to <12>, in the unit including the developing device containing the glitter toner and the fixing device provided with the specific fixing device, the fixing temperature of the fixing device is less than 130°C. A unit is provided that forms a glitter image with a high glitter feeling due to the glitter toner as compared with the case.

1 is a schematic configuration diagram showing an example of an image forming apparatus according to an embodiment; FIG. 1 is a cross-sectional view schematically showing an example of glitter toner; FIG. 1 is a schematic configuration diagram showing an example of a unit and a fixing device of an image forming apparatus according to an exemplary embodiment; FIG.

The present embodiment, which is an example of the present invention, will be described below. These descriptions and examples are illustrative of embodiments and are not intended to limit the scope of the invention.

In the numerical ranges described in stages in the present embodiment, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. good. In addition, in the numerical ranges described in this embodiment, the upper and lower limits of the numerical ranges may be replaced with the values shown in the examples.
In the present embodiment, the term "process" includes not only an independent process, but also when the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. .
When the embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this.
In this embodiment, each component may contain a plurality of corresponding substances. When referring to the amount of each component in the composition in this embodiment, if there are multiple types of substances corresponding to each component in the composition, unless otherwise specified, the plurality of types present in the composition means the total amount of substances in

[unit]
The unit according to the present embodiment accommodates a developer having a glitter toner containing a flat glitter pigment, and develops an electrostatic charge image formed on the surface of an image carrier as a toner image by the developer. A developing device and a fixing device for fixing a toner image on the surface of a recording medium at a fixing temperature of 130° C. or more and 230° C. or less are provided.
Then, the fixing device includes a fixing belt, a first roll and a second roll that are arranged inside the fixing belt and support the fixing belt while applying tension to the fixing belt, and the fixing belt together with the first roll. A fixing device (specific fixing device) having pressure rolls that form a nip portion by sandwiching the fixing device is applied.

With the above configuration, the unit according to the present embodiment forms a glitter image with a high glitter feeling by the glitter toner. The reason is as follows.

The glitter of the image by the glitter toner is expressed by parallelization of the glitter pigment on the surface of the recording medium when the toner image is fixed on the recording medium. In other words, the glitter of the image by the glitter toner is achieved by orienting the glitter pigment so that the surface facing the thickness direction of the glitter pigment is aligned with the surface of the recording medium during fixation.

However, when a glitter image is formed with a glitter toner using a specific fixing device, the feeling of glitter may be reduced.

Therefore, in the unit according to the present embodiment, the fixing temperature of the specific fixing device is set at 130° C. or higher and 230° C. or lower (preferably 150° C. or higher and 210° C. or lower). As a result, the toner image formed by the glitter toner is sufficiently melted at the nip portion, and the glitter pigment is easily parallelized on the surface of the recording medium. As a result, it is possible to form a glitter image with a high glitter feeling by the glitter toner.

Here, the fixing temperature indicates the temperature of the nip portion.

In addition, in the unit according to the present embodiment, the fixing belt is preferably rotationally driven at a linear velocity of 180 mm/sec to 450 mm/sec (preferably 200 mm/sec to 430 mm/sec). By setting the fixing temperature to 130° C. or higher and 230° C. or lower and reducing the linear velocity of the fixing belt within the above range, sufficient heat is imparted to the toner image by the glitter toner. As a result, it is possible to form a glitter image with a high glitter feeling by the glitter toner.

In particular, when the nip portion of the specific fixing device is flat, it is difficult for the glitter pigment to become parallel to the surface of the recording medium during fixing, and the glitter tends to be reduced.
If the nip portion (that is, the contact surface between the fixing belt and the pressure roll) is curved along the shape of one of the facing first roll and the pressure roll, the nip portion (especially, the nip where the curvature of curvature changes greatly) Since a large shearing force is applied to the glitter toner at the outlet, the glitter pigment tends to become parallel to the surface of the recording medium during fixing. On the other hand, when the nip portion is flat, shear force is less likely to be applied to the glitter toner. Therefore, if the nip portion is flat, the feeling of glitter tends to be reduced.
However, even with a specific fixing device having a flat nip portion, by setting the fixing temperature to 130° C. or more and 230° C. or less, it is possible to form a glitter image with a high glitter feeling by the glitter toner.

Here, "the nip portion is flat" means that the first roll and the pressure roll facing each other are crushed without biting into one of the rolls, and the first roll and the pressure roll are displaced before the arrangement. It shows that the contact surfaces of the fixing belt and pressure roll are not curved along this shape.

[Image forming apparatus]
An image forming apparatus including units according to the present embodiment will be described below.

An image forming apparatus according to the present embodiment includes an image carrier and a developing device among the units according to the present embodiment, and forms a toner image on the surface of the image carrier; A transfer device for transferring a toner image formed on the surface of an image carrier onto the surface of a recording medium, and a fixing device for fixing the toner image on the surface of the recording medium, which are among the units according to the present embodiment. and provide

The toner image forming apparatus includes, for example, an image carrier, a charging device that charges the surface of the image carrier, an electrostatic charge image forming device that forms an electrostatic charge image on the surface of the charged image carrier, and a glitter toner. and a developing device that forms a toner image by developing an electrostatic charge image formed on the surface of the image carrier with a developer contained therein.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus for directly transferring a toner image formed on the surface of an image carrier onto a recording medium; An intermediate transfer type device that performs primary transfer on the surface and secondary transfer of the toner image transferred on the surface of the intermediate transfer body to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. A device equipped with a cleaning device; A device equipped with a static elimination device that irradiates the surface of the image carrier with static elimination light to eliminate static electricity after transfer of the toner image and before charging; Raises the temperature of the image carrier to reduce the relative temperature A well-known image forming apparatus, such as an apparatus having an image carrier heating member, is applied.
In the case of an intermediate transfer type apparatus, the transfer device includes, for example, an intermediate transfer member on which a toner image is transferred, and a primary transfer device that primarily transfers the toner image formed on the surface of the image carrier onto the surface of the intermediate transfer member. A configuration having a device and a secondary transfer device that secondarily transfers the toner image transferred on the surface of the intermediate transfer member to the surface of the recording medium is applied.

An example of the image forming apparatus according to the present embodiment will be described below, but the present invention is not limited to this. In the following description, the main parts shown in the drawings will be described, and the description of the other parts will be omitted.
In the following description, the glitter toner is referred to as "silver toner". and,

FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus according to the present embodiment, and is a diagram showing an image forming apparatus of a quintuple tandem system and an intermediate transfer system.
Figure 1
is an electrophotographic system that outputs yellow (Y), magenta (M), cyan (C), black (K), and silver (B) images based on color-separated image data. 1st to 5th image forming units 150Y, 150M, 150C, 150K, and 150B (an example of a toner image forming device). These image forming units 150Y, 150M, 150C, 150K, and 150B are horizontally arranged side by side at predetermined distances from each other. These image forming units 150Y, 150M, 150C, 150K, and 150B may be process cartridges that are detachable from the image forming apparatus.

Below the image forming units 150Y, 150M, 150C, 150K, and 150B, an intermediate transfer belt 133 extends through each unit. The intermediate transfer belt 133 is wound around a drive roll 113, a support roll 112, and an opposing roll 114, which are in contact with the inner surface of the intermediate transfer belt 133. It runs in the opposite direction (arrow B direction in FIG. 1). An intermediate transfer belt cleaning device 116 is provided on the image holding surface side of the intermediate transfer belt 133 so as to face the drive roll 113 . In addition, a voltage is applied to the upstream side of the intermediate transfer belt 133 in the rotation direction with respect to the intermediate transfer belt cleaning device 116 to generate an electric field with the intermediate transfer belt 133 by generating a potential difference with the support roll 113 . A device 160 is provided.
Developing devices (examples of developing devices) 120Y, 120M, 120C, 120K, and 120B of the image forming units 150Y, 150M, 150C, 150K, and 150B are stored in toner cartridges 140Y, 140M, 140C, 140K, and 140B, respectively. Then, yellow, magenta, cyan, black, and silver toners are supplied.

Since the first to fifth image forming units 150Y, 150M, 150C, 150K, and 150B have similar configurations, operations, and functions, they are arranged upstream in the running direction of the intermediate transfer belt. The first image forming unit 150Y that forms a yellow image will be described as a representative.

The first image forming unit 150Y has a photoreceptor 111Y acting as an image carrier. Around the photoreceptor 111Y, there is a charging roll (an example of a charging device) 118Y that charges the surface of the photoreceptor 111Y to a predetermined potential. An exposure device (an example of an electrostatic charge image forming device) 119Y that forms an electrostatic charge image using the A primary transfer roll (an example of a primary transfer device) 117Y that transfers onto the intermediate transfer belt 133, and a photoreceptor cleaning device (an example of a cleaning device) 115Y that removes toner remaining on the surface of the photoreceptor 111Y after the primary transfer are arranged in this order. It is
The primary transfer roll 117Y is arranged inside the intermediate transfer belt 133 and provided at a position facing the photoreceptor 111Y. A bias power source (not shown) that applies a primary transfer bias is connected to the primary transfer rolls 117Y, 117M, 117C, 117K, and 117B of each image forming unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll under the control of a controller (not shown).

The operation of forming a yellow image in the first image forming unit 150Y will be described below.
First, prior to operation, the surface of the photoreceptor 111Y is charged to a potential of -600V to -800V by the charging roll 118Y.
The photoreceptor 111Y is formed by stacking a photoreceptor layer on a conductive substrate (for example, a volume resistivity of 1×10 ⁻⁶ Ωcm or less at 20° C.). This photosensitive layer normally has a high resistance (resistivity of general resin), but has the property of changing the specific resistance of the portion irradiated with the laser beam when irradiated with the laser beam. Therefore, the surface of the charged photoreceptor 111Y is irradiated with a laser beam from the exposure device 119Y in accordance with yellow image data sent from a control unit (not shown). Thereby, an electrostatic charge image of a yellow image pattern is formed on the surface of the photoreceptor 111Y.

An electrostatic charge image is an image formed on the surface of the photoreceptor 111Y by charging. The laser beam from the exposure device 119Y reduces the specific resistance of the irradiated portion of the photosensitive layer, and the surface of the photoreceptor 111Y is charged. This is a so-called negative latent image, which is formed by the flow of the charged charge and the residual charge in the portion not irradiated with the laser beam.
The electrostatic charge image formed on the photoreceptor 111Y rotates to a predetermined development position as the photoreceptor 111Y travels. At this development position, the electrostatic charge image on the photoreceptor 111Y is developed as a toner image by the developing device 120Y and visualized.

The developing device 120Y contains, for example, developer containing at least yellow toner and carrier. The yellow toner is triboelectrically charged by being agitated inside the developing device 120Y, and has the same polarity (negative polarity) as the charged charge on the photoreceptor 111Y. One example) is held above. As the surface of the photoreceptor 111Y passes through the developing device 120Y, the yellow toner electrostatically adheres to the static-eliminated latent image portion on the surface of the photoreceptor 111Y, and the latent image is developed with the yellow toner. . Photoreceptor 111Y on which the yellow toner image is formed continues to travel at a predetermined speed, and the toner image developed on photoreceptor 111Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 111Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 117Y, and an electrostatic force directed from the photoreceptor 111Y to the primary transfer roll 117Y acts on the toner image. The toner image on body 111 Y is transferred onto intermediate transfer belt 133 . The transfer bias applied at this time has a (+) polarity opposite to the polarity (-) of the toner, and is controlled to +10 μA, for example, by a control section (not shown) in the first image forming unit 150Y.
On the other hand, the toner remaining on the photoreceptor 111Y is removed and collected by the photoreceptor cleaning device 115Y.

The primary transfer biases applied to the primary transfer rolls 117M, 117C, 117K, and 117B after the second image forming unit 150M are also controlled according to the first image forming unit 150Y.
In this way, the intermediate transfer belt 133 onto which the yellow toner image has been transferred by the first image forming unit 150Y is sequentially conveyed through the second to fifth image forming units 150M, 150C, 150K, and 150B, and the toner images of the respective colors are formed. are superimposed and multi-transferred.

The intermediate transfer belt 133, on which the five-color toner images are multiple-transferred through the first to fifth image forming units, consists of the intermediate transfer belt 133, the opposing roller 114 in contact with the inner surface of the intermediate transfer belt, and the image of the intermediate transfer belt 133. It reaches a secondary transfer portion configured with a secondary transfer roll (an example of a secondary transfer device) 134 arranged on the holding surface side. On the other hand, a recording paper (an example of a recording medium) P is fed through the supply mechanism into the gap between the secondary transfer roll 134 and the intermediate transfer belt 133 at a predetermined timing, and the secondary transfer bias is applied to the opposite roll. 114. The transfer bias applied at this time has the same (-) polarity as the polarity (-) of the toner. is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection device (not shown) that detects the resistance of the secondary transfer portion, and is voltage-controlled.

After that, the recording paper P is sent to a pressure contact portion (nip portion) between a pair of fixing rolls in a fixing device (an example of a fixing device) 135, and the toner image is fixed on the recording paper P to form a fixed image. .

Examples of the recording paper P onto which the toner image is transferred include plain paper used in electrophotographic copiers, printers, and the like. In addition to the recording paper P, an OHP sheet or the like can also be used as the recording medium.
In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. preferably used.

The recording paper P on which the fixing of the color image has been completed is carried out toward the discharge section, and a series of color image forming operations is completed.

Here, the developing device 120B of the image forming unit 150B corresponds to an example of the developing device in the unit according to the present embodiment.
The fixing device 135 corresponds to an example of the transfer device in the unit according to the present embodiment.
A device including the developing device 120B and the fixing device 135 corresponds to an example of the unit according to the present embodiment.

The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 140Y, 140M, 140C, 140K, and 140B are detachable. It is connected to a toner cartridge corresponding to the developing device (color) through a toner supply pipe (not shown). In addition, when the toner contained in the toner cartridge runs out, the toner cartridge is replaced.

[Developing device]
Hereinafter, the unit and the developing device of the image forming apparatus according to this embodiment will be described in more detail. In addition, the code|symbol is abbreviate|omitted and demonstrated.
The developing device is provided, for example, on the downstream side in the rotation direction of the image carrier from the light irradiation position of the electrostatic image forming device. A container for containing the developer is provided in the developing device. This container contains a developer having a glitter toner containing a glitter pigment. The glitter toner is, for example, stored in a developing device in a charged state. Details of the glitter toner will be described later.

The developing device 18 includes, for example, a developing member that develops an electrostatic charge image formed on the surface of the image carrier with a developer containing glitter toner, and a power source that applies a developing voltage to the developing member. The development member is electrically connected, for example, to a power supply.

The developing member of the developing device is selected according to the type of developer, and for example, a developing roll having a developing sleeve with a built-in magnet can be used.

In the developing device (including the power source), for example, a developing voltage is applied to the developing member. The developing member to which the developing voltage is applied is charged to a developing potential corresponding to the developing voltage. The developing member charged to the development potential holds, for example, the developer contained in the developing device on the surface, and supplies the glitter toner contained in the developer from the developing device to the surface of the image carrier. do.

The toner supplied onto the image carrier adheres, for example, to the electrostatic charge image on the image carrier due to electrostatic force. More specifically, for example, the potential difference in the region where the image carrier and the developing member face each other, that is, the potential difference between the potential of the surface of the image carrier and the developing potential of the developing member in the region, causes the bright toner contained in the developer to is applied to the electrostatically imaged areas of the image carrier. When the developer contains carrier, the carrier is returned to the developing device while being held by the developing member.

For example, an electrostatic charge image on the image carrier is developed with a bright toner supplied from a developing member to form a toner image corresponding to the electrostatic charge image on the image carrier.

[Glitter Toner]
The glitter toner will be described below.
The glitter toner contains a flat glitter pigment.
Specifically, the glitter toner has glitter toner particles containing a glitter pigment. Also, the glitter toner may contain an external additive.

(Glittering Toner Particles)
The glitter toner particles contain, for example, a binder resin and a glitter pigment. The glitter toner particles may contain a colorant, a release agent, and other components other than the glitter pigment.

- Binder resin -
Examples of binder resins include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g. acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), etc. or a copolymer of two or more of these monomers in combination.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these resins. A graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence thereof may also be used.
These binder resins may be used singly or in combination of two or more.

In particular, it is preferable to use an amorphous resin and a crystalline resin as the binder resin.
However, the mass ratio of the amorphous resin to the crystalline resin (crystalline resin/amorphous resin) is preferably 3/97 or more and 50/50 or less, more preferably 7/93 or more and 30/70 or less.

Here, the amorphous resin is not a clear endothermic peak in thermal analysis measurement using differential scanning calorimetry (DSC), but has only a stepwise endothermic change, is a solid at room temperature, and has a glass transition Refers to those that are thermoplastic at a temperature above the temperature.
On the other hand, a crystalline resin means a resin having a clear endothermic peak instead of a stepwise change in endothermic amount in differential scanning calorimetry (DSC).
Specifically, for example, the crystalline resin means that the half-value width of the endothermic peak measured at a heating rate of 10° C./min is within 10° C., and the amorphous resin means the half-value width is higher than 10°C, or a resin in which a clear endothermic peak is not observed.

Amorphous resin will be explained.
Examples of amorphous resins include known amorphous resins such as amorphous polyester resins, amorphous vinyl resins (such as styrene acrylic resins), epoxy resins, polycarbonate resins, and polyurethane resins. Among these, amorphous polyester resins and amorphous vinyl resins (especially styrene-acrylic resins) are preferred, and amorphous polyester resins are more preferred.
In addition, it is also a preferable embodiment to use an amorphous polyester resin and a styrene-acrylic resin together as the amorphous resin. It is also a preferred embodiment to apply an amorphous resin having an amorphous polyester resin segment and a styrene-acrylic resin segment as the amorphous resin.

Crystalline resins include known crystalline resins such as crystalline polyester resins and crystalline vinyl resins (eg, polyalkylene resins, long-chain alkyl (meth)acrylate resins, etc.). Among these, crystalline polyester resins are preferred from the viewpoint of the mechanical strength and low-temperature fixability of the glitter toner.

The content of the binder resin is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further 60% by mass or more and 85% by mass or less with respect to the entire glitter toner particles. preferable.

- Luster Pigment -
Luminous pigments include, for example, pigments capable of imparting luster such as metallic luster. Specific examples of luster pigments include, for example, metal powders such as aluminum (metal of simple Al), brass, bronze, nickel, stainless steel, zinc; mica coated with titanium oxide, yellow iron oxide, etc.; barium sulfate, layered silicon platelet-like titanium oxide; basic carbonates; bismuth acid oxychloride; natural guanine; flaky glass powder; Examples include powder, and there is no particular limitation as long as it has luster.
Among these, metal powder is preferable as the luster pigment, particularly from the viewpoint of specular reflection intensity, and among these, aluminum is most preferable.

The average length of the bright pigment in the major axis direction is preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, and even more preferably 5 μm or more and 15 μm or less.
When the average length in the thickness direction of the bright pigment is 1, the ratio of the average length in the long axis direction (aspect ratio) is preferably 5 or more and 200 or less, more preferably 10 or more and 100 or less, 30 or more and 70 or less is more preferable.

Each average length and aspect ratio of the bright pigment are measured by the following methods. Using a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Co., Ltd.), a photograph of the bright pigment is taken at a measurable magnification (300 to 100,000 times), and the image of the bright pigment obtained is taken. In the two-dimensional state, the length in the major axis direction and the length in the thickness direction of each particle are measured, and the average length in the major axis direction and the aspect ratio of the bright pigment are calculated.
Here, the length of the bright pigment in the major axis direction means the longest portion when the bright pigment is observed from the thickness direction of the bright pigment. The length of the bright pigment in the thickness direction refers to the longest portion when the bright pigment is observed from the direction orthogonal to the thickness direction of the bright pigment.

The volume average particle size of the bright pigment is preferably 1.0 μm or more and 20.0 μm or less, more preferably 2.0 μm or more and 15.0 μm or less.

The volume average particle size of the luster pigment is measured as follows.
Based on the particle size distribution measured by a measuring instrument such as Multisizer II (manufactured by Coulter), the cumulative distribution of the volume is drawn from the small diameter side for each divided particle size range (channel), and the cumulative distribution is 50%. Let the particle size be the volume average particle size.
As a method for measuring the volume average particle diameter of the glitter pigment in the glitter toner particles after production, a solvent capable of dissolving only the resin without dissolving the glitter pigment and the glitter toner are mixed and stirred, and After the resin is dissolved in the solvent, the bright pigment is subjected to solid-liquid separation, and the volume average particle diameter is measured with the same particle size distribution analyzer as described above.

The content of the glitter pigment is preferably 1% by mass or more and 70% by mass or less, more preferably 5% by mass or more and 50% by mass or less, and 5% by mass with respect to the total mass of the glitter toner particles. It is more preferable that the content is at least 40% by mass or less.

-Colorants other than luster pigments-
Colorants other than bright pigments include, for example, carbon black, chrome yellow, Hansa yellow, benzidine yellow, thren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, Brilliant Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Pigments such as blue, phthalocyanine green, malachite green oxalate; acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black-based, polymethine-based, triphenylmethane-based, diphenylmethane-based, and thiazole-based dyes;
The coloring agents other than the luster pigment may be used singly or in combination of two or more.

Colorants other than bright pigments may be surface-treated colorants, if necessary, and may be used in combination with dispersants. Also, a plurality of types of colorants may be used in combination.

The content of the coloring agent other than the glitter pigment is adjusted according to the color of the glitter toner.

-Release agent-
Release agents include, for example, hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral/petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montan acid esters. ; and the like. The release agent is not limited to this.

The melting temperature of the releasing agent is preferably 50° C. or higher and 110° C. or lower, more preferably 60° C. or higher and 100° C. or lower.
The melting temperature of the release agent is determined from the DSC curve obtained by differential scanning calorimetry (DSC), according to the "melting peak temperature" described in JIS K7121: 1987 "Method for measuring the transition temperature of plastics". Ask.

The content of the release agent is preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 15% by mass or less, relative to the entire glitter toner particles.

-Other additives-
Other additives include, for example, known additives such as magnetic substances, charge control agents, and inorganic powders. These additives are contained in the glitter toner particles as internal additives.

-Characteristics of Glittering Toner Particles-
The glitter toner particles are flat and have an average equivalent circle diameter D longer than an average maximum thickness C thereof.
When the glitter toner particles are flat with an equivalent circle diameter longer than the thickness (see FIG. 2), the flat surface side of the glitter toner particles is pushed to the recording medium by the pressure during fixing in the fixing process of image formation. It is thought that they are arranged so as to face the surface. In FIG. 2, 2 indicates the glitter toner particles, 4 the glitter pigment, and L the thickness of the glitter toner particles.

The ratio (C/D) between the average maximum thickness C and the average equivalent circle diameter D is preferably in the range of 0.001 or more and 0.700 or less, and is in the range of 0.001 or more and 0.500 or less. is more preferable, the range of 0.100 or more and 0.600 or less is more preferable, and the range of 0.300 or more and 0.450 or less is particularly preferable.
When the ratio (C/D) is 0.001 or more, the strength of the toner particles is ensured, breakage due to stress during image formation is suppressed, and electrification decreases due to exposure of the bright pigment, resulting in The fog that occurs is suppressed. On the other hand, when the ratio (C/D) is 0.700 or less, excellent glitter can be obtained.

The average maximum thickness C and the average equivalent circle diameter D are measured by the following method.
Glittering toner particles are placed on a smooth surface and vibrated to evenly disperse them. 1,000 toner particles are magnified 1,000 times using a color laser microscope "VK-9700" (manufactured by Keyence Corporation), and the maximum thickness C of the toner particles and the circle equivalent of the surface viewed from above It is calculated by measuring the diameter D and calculating the arithmetic mean value thereof.

Brilliance such that the angle between the major axis direction of the toner particle and the major axis direction of the glitter pigment is in the range of −30° to +30° when the cross section of the glitter toner particle in the thickness direction is observed. It is preferable that the proportion of the pigment (based on the number) is 60% or more of all the observed luster pigments. Furthermore, the ratio is more preferably 70% or more and 95% or less, and particularly preferably 80% or more and 90% or less.
When the above ratio is 60% or more, excellent brilliance can be obtained.

Here, a method for observing a cross section of glitter toner particles will be described.
After embedding the toner particles using a bisphenol A type liquid epoxy resin and a curing agent, a cutting sample is prepared. Next, a cutting machine using a diamond knife, for example, an ultramicrotome device (UltracutUCT, manufactured by Leica) is used to cut the cut sample at -100°C to prepare a sample for observation. The observation sample is observed, for example, with an ultra-high resolution field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) at a magnification such that about 1 to 10 bright pigment toner particles can be seen in one field of view.
Specifically, the cross section of the glitter toner particles (the cross section along the thickness direction of the glitter toner particles) was observed, and the observed 100 glitter toner particles were measured in the major axis direction in the cross section of the glitter toner particles. and the long axis direction of the bright pigment is in the range of -30 ° to +30 °, for example, image analysis software such as image analysis software (Win ROOF) manufactured by Mitani Shoji Co., Ltd. Alternatively, the output samples of the observed image and a protractor are used to count and calculate the ratio.

The volume average particle diameter of the glitter toner particles is preferably 3 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less.

Various average particle diameters and various particle size distribution indexes of the glitter toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and ISOTON-II (manufactured by Beckman Coulter, Inc.) was used as the electrolytic solution. measured.
In the measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm was measured by Coulter Multisizer II using an aperture with an aperture diameter of 100 μm. Measure. Note that the number of particles to be sampled is 50,000.
Based on the measured particle size distribution, the volume and number of the particle size ranges (channels) divided based on the cumulative distribution are drawn from the small diameter side, and the particle size at which the cumulative 16% is the volume particle size D16v, the number particle size D16p, the particle diameter at which the cumulative 50% is obtained is defined as the volume average particle diameter D50v, the cumulative number average particle diameter D50p, the particle diameter at which the cumulative 84% is obtained is defined as the volume particle diameter D84v and the number particle diameter D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v/D16v) ^1/2 and the number particle size distribution index (GSDp) is calculated as (D84p/D16p) ^1/2 .

The ratio (aspect ratio) of the average length in the major axis direction to the average length in the thickness direction of the glitter toner particles is preferably 1.5 or more and 15 or less, and 2 or more and 10 or less. It is more preferable that there is one, and it is still more preferable that it is 3 or more and 8 or less.
The average length in the thickness direction and the average length in the longitudinal direction of the glitter toner particles are determined by putting the glitter toner particles on a smooth surface and vibrating them so that they are evenly dispersed. 1,000 glitter toner particles were magnified 1,000 times using a color laser microscope "VK-9700" (manufactured by Keyence Corporation) to determine the maximum thickness and top view of the glitter toner particles. It is calculated by measuring the length in the long axis direction and calculating the arithmetic mean value thereof.

(external additive)
Examples of external additives include inorganic particles. Examples of the inorganic particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _SiO2 , _K2O . _{( TiO2} )n, _Al2O3.2SiO2 , _{CaCO3 , MgCO3 , BaSO4} , MgSO4 and the like.

The surfaces of the inorganic particles used as the external additive are preferably subjected to a hydrophobic treatment. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type, and may use 2 or more types together.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

External additives include resin particles (polystyrene, polymethyl methacrylate (PMMA), resin particles such as melamine resin), cleaning active agents (for example, metal salts of higher fatty acids represented by zinc stearate, fluorine-based high molecular weight particles) and the like.

The external addition amount of the external additive is, for example, preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 2.0% by mass or less, relative to the toner particles.

(Characteristics of glitter toner)
The glitter toner is sufficiently melted in the nip portion of the fixing device to form a glitter image with a high glitter feeling due to the glitter toner.
Therefore, the viscosity of the glitter toner at 130° C. is preferably 100 Pa·s or more and 1000 Pa·s or less, more preferably 150 or more and 800 or less.
The viscosity of the glitter toner can be adjusted by the type and molecular weight of the binder resin.

Here, the viscosity of the glitter toner is measured at 130° C. using “(apparatus name) ARES” (manufactured by Rheometrics).

“Glitteriness” of a glitter image by a glitter toner means that the image has glitter like metallic luster when the image is visually recognized.
Specifically, when a bright toner is used to form a solid image (for example, an image having a coating amount of the bright toner of 3.5 g/m ² or more), the incident angle − The ratio (X/Y) between the reflectance X at the light receiving angle of +30° and the reflectance Y at the light receiving angle of -30° measured when irradiated with incident light at 45° is 2 or more and 100 or less. preferable.

When the ratio (X/Y) is 2 or more, it means that there is more reflection to the side opposite to the incident side (positive angle side) than to the incident side (negative angle side). , that is, it means that the diffused reflection of incident light is suppressed. When incident light is reflected in various directions by irregular reflection, the color of the reflected light looks dull when visually confirmed. Therefore, when the ratio (X/Y) is less than 2, the gloss may not be confirmed even if the reflected light is visually recognized, resulting in poor luster.
On the other hand, if the ratio (X/Y) exceeds 100, the viewing angle at which the reflected light can be visually recognized becomes too narrow, and the specularly reflected light component is large, so that it may appear dark depending on the viewing angle. Moreover, it is difficult to produce a toner having a ratio (X/Y) exceeding 100.

The ratio (X/Y) is more preferably 4 or more and 50 or less, still more preferably 6 or more and 20 or less, and particularly preferably 8 or more and 15 or less.

-Measurement of ratio (X/Y) by goniophotometer-
Here, first, the incident angle and the light receiving angle will be explained. In the present embodiment, the angle of incidence is -45° when measuring with a goniophotometer, because the measurement sensitivity is high for images with a wide range of glossiness.
The light-receiving angles are set to −30° and +30° because the measurement sensitivity is the highest for evaluating an image with a feeling of brightness and an image without feeling of brightness.

Next, a method for measuring the ratio (X/Y) will be described.
Using a spectroscopic gonio-color difference meter GC5000L manufactured by Nippon Denshoku Industries Co., Ltd. as a goniophotometer for the image to be measured (glitter image), incident light with an incident angle of -45° to the image is incident. Then, the reflectance X at the light receiving angle of +30° and the reflectance Y at the light receiving angle of -30° are measured. The reflectance X and the reflectance Y are measured at intervals of 20 nm for light with a wavelength in the range of 400 nm to 700 nm, and the reflectance at each wavelength is taken as an average value. A ratio (X/Y) is calculated from these measurement results.

The glitter toner preferably satisfies the following requirements (1) and (2) from the viewpoint of satisfying the ratio (X/Y).
(1) The average equivalent circle diameter D is longer than the average maximum thickness C of the glitter toner particles.
(2) When observing the cross section of the glitter toner particles in the thickness direction, the angle between the long axis direction of the toner particles and the long axis direction of the glitter pigment is in the range of −30° to +30°. is 60% or more of all observed bright pigments.

(Method for producing glitter toner)
The glitter toner is obtained, for example, by externally adding an external additive to the glitter toner particles after manufacturing the glitter toner particles.

Glittering toner particles may be produced by either a dry method (eg, kneading pulverization method, etc.) or a wet method (eg, aggregation coalescence method, suspension polymerization method, dissolution suspension method, etc.). These manufacturing methods are not particularly limited, and known manufacturing methods are employed. Among these, it is preferable to obtain glittering toner particles by the aggregation coalescence method.

[Developer]
The developer may be a one-component developer containing only glitter toner, or a two-component developer in which glitter toner and carrier are mixed.

The carrier is not particularly limited and includes known carriers. Examples of carriers include coated carriers in which the surface of a core material made of magnetic powder is coated with a coating resin; magnetic powder-dispersed carriers in which magnetic powder is dispersed and blended in a matrix resin; porous magnetic powder impregnated with resin. resin-impregnated carrier;
The magnetic powder-dispersed carrier and the resin-impregnated carrier may be carriers in which constituent particles of the carrier are used as a core material and coated with a coating resin.

The mixing ratio (mass ratio) of toner and carrier in the two-component developer is preferably toner:carrier=1:100 to 30:100, more preferably 3:100 to 20:100.

[Fixing device]
Hereinafter, the unit and the fixing device of the image forming apparatus according to this embodiment will be described in more detail.
FIG. 3 is a schematic configuration diagram showing an example of a unit and a fixing device (that is, a specific fixing device) of the image forming apparatus according to this embodiment. Note that FIG. 3 shows only the main part of the fixing device.

The fixing device shown in FIG. and a pressure roll 208 arranged opposite to the fixing belt 202 .

The fixing belt 202 is supported while being tensioned by a fixing roll 204 and a pressure roll 208 .
The pressure roll 208 and the fixing roll 204 are arranged to form a nip portion (that is, a contact portion) N across the fixing belt 202 .

The fixing belt 202 is, for example, an endless belt in which a base layer, an elastic layer, and a release layer are laminated in this order.
The base material layer is composed of a heat-resistant resin layer such as polyimide resin, aromatic polyamide resin, polyester resin, polyethylene terephthalate resin, polyethersulfone resin, polyetherketone resin, polysulfone resin, polyimideamide resin, or the like. .
The elastic layer is composed of, for example, a layer of a heat-resistant elastic material such as silicone rubber or fluororubber.
The release layer is composed of, for example, a layer of a heat-resistant release agent such as fluororubber, fluororesin, silicone resin, or polyimide resin.
These base layer, elastic layer, and release layer may contain well-known additives such as conductive agents and fillers.

The fixing roll 204 is composed of, for example, a roll having a metal roll and an elastic layer provided on the outer peripheral surface of the metal roll.
The heating roll 206 is composed of, for example, a roll having a metal roll containing a heat source (halogen lamp or the like) and an elastic layer provided on the outer peripheral surface of the metal roll.
The pressure roll 208 is composed of, for example, a roll having a metal roll containing a heat source (halogen lamp or the like) and an elastic layer provided on the outer peripheral surface of the metal roll.
The metal roll is composed of, for example, a hollow roll made of copper, aluminum, stainless steel (SUS), sulfur composite steel (SUM), various alloys, or the like.
The elastic layer is composed of, for example, a layer of a heat-resistant elastic material such as silicone rubber or fluororubber. The elastic layer may contain well-known additives such as conductive agents and fillers.

In the fixing device shown in FIG. 3, the fixing roll 204 and the pressure roll 208 are arranged in pressure contact with each other through the fixing belt 202 with their elastic layers crushed. Thereby, a flat nip portion N is formed.
In order to flatten the nip portion N, for example, the fixing roll 204 (an example of the first roll) and the pressure roll 208 should adopt the following mode.
1) The difference (absolute value) in surface hardness between the fixing roll 204 and the pressure roll 208 is within 15°.
2) The surface hardness of the fixing roll 204 is 35° or more and 45° or less.
3) The surface hardness of the pressure roll 208 is 40° or more and 50° or less.
4) The fixing roll 204 and the fixing roll 204 are arranged such that the pressure at the nip portion N is 2.0 kgf/cm ² or more and 7.0 kgf/cm ² or less (preferably 4.0 kgf/cm ² or more and 7.0 kgf/cm ² or less). The pressure roll 208 is placed with a load applied.
5) The outer diameter ratio between the fixing roll 204 and the pressure roll 208 (fixing roll 204/pressure roll 208) is 0.9 or more and 1.3 or less.

When the fixing roll 204 (an example of the first roll) and the pressure roll 208 adopt the modes 1) to 5) above, the nip portion N becomes flat.

Here, the surface hardness of the roll is Asker C hardness, which is measured by an Asker C hardness tester.

In the fixing device shown in FIG. 3, while the fixing belt 202, the fixing roll 204, the heating roll 206, and the pressure roll 208 are rotating, the fixing belt 202 is heated from the inner peripheral surface by the heat source of the heating roll 206, and the heat is applied. The nip portion N is directly heated by the heat source of the impression roll 208 . The linear velocity of the fixing belt 202 at this time is, for example, 180 mm/sec or more and 450 mm/sec or less.
Then, the recording medium P having the toner image T transferred thereon is passed through the nip portion while the fixing temperature (that is, the temperature of the nip portion) is set at 130° C. or more and 230° C. or less. Thereby, the toner image T is fixed on the recording medium P to form an image.

Here, by setting the fixing temperature (that is, the temperature of the nip portion) to 130° C. or more and 230° C. or less, even in the fixing device (that is, the specific fixing device) shown in FIG. The image is sufficiently melted to facilitate parallelization of the luster pigment to the surface of the recording medium. As a result, it is possible to form a glitter image with a high glitter feeling by the glitter toner.

In addition, by rotating the fixing belt at a linear velocity of 180 mm/sec to 450 mm/sec, even in the fixing device shown in FIG. Sufficient heat is applied to further melt the toner image, making it easier for the glitter pigment to become parallel to the surface of the recording medium. As a result, it is possible to form a glitter image with a high glitter feeling by the glitter toner.

Note that the fixing device shown in FIG. 3 is not limited to the above configuration as long as it corresponds to a specific fixing device.
In the fixing device shown in FIG. 3, instead of the heating roll 206, for example, a metal roll that supports the fixing belt 202 and heats it by electromagnetic induction is placed facing the fixing belt 202 via an electromagnetic induction coil having an electromagnetic induction coil. It may be a configuration including a part.

Here, although not shown, the image forming apparatus including the fixing device according to the present embodiment includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage, a communication interface, an input It has a part and a display part. Each component is communicatively connected to each other via a bus 28 .
A CPU is a central processing unit that executes various programs and controls each section. That is, the CPU reads a program from ROM or storage and executes the program using RAM as a work area. The CPU performs control of each of the above components and various arithmetic processing according to programs recorded in the ROM or storage.
The ROM stores various programs and various data.
RAM temporarily stores programs or data as a work area.
The storage is composed of a storage device such as a HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory, and stores various programs including an operating system and various data.
A communication interface is an interface for communicating with other devices. The communication uses, for example, a wired communication standard such as Ethernet (registered trademark) or FDDI, or a wireless communication standard such as 4G, 5G, or Wi-Fi (registered trademark).
The input unit includes a pointing device such as a mouse and a keyboard, and is used for various inputs.
The display unit is, for example, a liquid crystal display, and displays various information. The display unit may employ a touch panel system and function as an input unit.

For example, the ROM or storage stores a program for controlling the fixing temperature of the fixing device, a program for controlling the rotation speed of the fixing belt (for example, a program for controlling the motor that drives the rotation of the fixing roll), and the like. there is The fixing device is controlled by the CPU reading and executing a program stored in the ROM or storage.

Note that various processors other than the CPU may execute the processing executed by the CPU reading the software (program) in each of the above-described embodiments. The processor in this case is a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit) for executing specific processing. A dedicated electric circuit or the like, which is a processor having a specially designed circuit configuration, is exemplified. Also, the processing may be performed on one of these various types of processors, or on a combination of two or more processors of the same or different type (eg, multiple FPGAs and combinations of CPUs and FPGAs, etc.). can be run with More specifically, the hardware structure of these various processors is an electric circuit in which circuit elements such as semiconductor elements are combined.

Although the present embodiment has been described above, it is not to be construed as being limited to the above-described embodiment, and various modifications, changes, and improvements are possible.

Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following description, "parts" and "%" are all based on mass unless otherwise specified.

<Developer>
[Developer (1)]
(Synthesis of binder resin)
Dimethyl fumarate: 74 parts Dimethyl terephthalate: 192 parts Bisphenol A ethylene oxide 2 mol adduct: 216 parts Bisphenol A propylene oxide 2 mol adduct: 48 parts Ethylene glycol: 38 parts Tetrabutoxy titanate (catalyst ): 0.037 parts,

The above components are placed in a heat-dried two-necked flask, and the temperature is raised while maintaining an inert atmosphere by introducing nitrogen gas into the vessel and stirring, followed by cocondensation reaction at 160° C. for 7 hours, and then gradually up to 10 Torr. The temperature was raised to 220° C. while the pressure was reduced to 220° C., and the temperature was maintained for 4 hours. The pressure was once returned to normal pressure, 9 parts of trimellitic anhydride was added, the pressure was gradually reduced to 10 Torr again, and the pressure was maintained at 220° C. for 1 hour to synthesize a binder resin.

(Preparation of resin particle dispersion)
・Binder resin: 160 parts ・Ethyl acetate: 233 parts ・Sodium hydroxide aqueous solution (0.3N): 0.1 part

The above components were placed in a 1,000 ml separable flask, heated at 70° C., and stirred with a three-one motor (manufactured by Shinto Kagaku Co., Ltd.) to prepare a resin mixture. 373 parts of ion-exchanged water was gradually added while stirring the resin mixture at 90 rpm, phase inversion emulsification was performed, and the solvent was removed to obtain a resin particle dispersion (solid concentration: 30%). The volume average particle diameter of the resin particle dispersion was 162 nm.

(Preparation of Release Agent Dispersion)
Carnauba wax (manufactured by Toa Kasei Co., Ltd., RC-160): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1.0 parts Ion-exchanged water: 200 parts

After mixing the above and heating to 95 ° C., dispersing using a homogenizer (manufactured by IKA, Ultra Turrax T50), dispersion treatment for 360 minutes with a Manton Gaulin high pressure homogenizer (Golin), volume average particles A release agent dispersion (solid concentration: 20%) was prepared by dispersing release agent particles having a diameter of 0.23 μm.

(Preparation of metal pigment particle dispersion)
· Aluminum pigment (manufactured by Showa Aluminum Powder Co., Ltd., 2173EA): 100 parts · Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R): 1.5 parts · Deionized water: 900 parts

After removing the solvent from the aluminum pigment paste, the above is mixed, dissolved, and dispersed for about 1 hour using an emulsifying disperser Cavitron (CR1010, manufactured by Taiheiyo Kiko Co., Ltd.) to obtain metal pigment particles (aluminum pigment). was dispersed to prepare a metal pigment particle dispersion (solid concentration: 10%). The average length in the longitudinal direction of the aluminum pigment (luminous pigment) was 8 μm, and the average length in the thickness direction was 0.1 μm.

(Preparation of glitter toner (1))
・Resin particle dispersion: 380 parts ・Releasing agent dispersion: 72 parts ・Metal pigment particle dispersion: 140 parts

The above-mentioned metal pigment particle dispersion, resin particle dispersion, and release agent dispersion are placed in a 2 L cylindrical stainless steel container, and dispersed for 10 minutes while applying a shearing force at 4000 rpm with a homogenizer (manufactured by IKA, Ultra Turrax T50). and mixed. Next, 1.75 parts of a 10% nitric acid aqueous solution of polyaluminum chloride was gradually added dropwise as a flocculating agent, and dispersed and mixed for 15 minutes at a homogenizer rotation speed of 5000 rpm to obtain a raw material dispersion.

After that, the raw material dispersion was transferred to a polymerization vessel equipped with a stirring device using two paddle stirring blades and a thermometer, and the stirring rotation speed was set to 810 rpm, heating was started with a mantle heater, and the aggregated particles were heated to 54 ° C. grew up. At this time, the pH of the raw material dispersion was controlled in the range of 2.2 to 3.5 with 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The above pH range was maintained for about 2 hours to form aggregated particles.

Next, the resin particle dispersion liquid was additionally added to adhere the resin particles of the binder resin to the surface of the aggregated particles. Further, the temperature was raised to 56° C., and the aggregated particles were arranged while confirming the size and shape of the particles with an optical microscope and Multisizer II. After that, the pH was raised to 8.0 in order to coalesce the agglomerated particles, and then the temperature was raised to 67.5°C. After confirming that the aggregated particles have fused with an optical microscope, the pH is lowered to 6.0 while maintaining the temperature at 67.5° C. After 1 hour, the heating is stopped and the mixture is cooled and flattened at a cooling rate of 0.1° C./min. did. After that, the particles were sieved through a 20 μm mesh, washed repeatedly with water, and dried in a vacuum dryer to obtain glittering toner particles.

1.5 parts of hydrophobic silica (RY50, manufactured by Nippon Aerosil Co., Ltd.) and 1.0 part of hydrophobic titanium oxide (T805, manufactured by Nippon Aerosil Co., Ltd.) are added to 100 parts of the glitter toner particles after heat treatment, A sample mill was used to mix at 10000 rpm for 30 seconds. After that, it was sieved with a vibrating sieve having an opening of 45 μm to prepare Glittering Toner (1).

The average maximum thickness C of the glitter toner particles was 4.27 μm, and the average circle equivalent diameter D of the glitter toner particles was 13.6 μm.

(Preparation of carrier)
・Ferrite particles (volume average particle diameter: 35 μm): 100 parts ・Toluene: 14 parts ・Perfluorooctylethyl acrylate/methyl methacrylate copolymer: 1.6 parts ・Carbon black (trade name: VXC-72, manufactured by Cabot Corporation ): 0.12 parts Crosslinked melamine resin particles (average particle size: 0.3 μm, insoluble in toluene): 0.3 parts

First, carbon black diluted with toluene was added to the perfluorooctylethyl acrylate/methyl methacrylate copolymer and dispersed with a sand mill. Next, the components other than the ferrite particles were dispersed with a stirrer for 10 minutes to prepare a coating layer forming solution. Next, this coating layer forming solution and ferrite particles are placed in a vacuum degassing kneader, stirred for 30 minutes at a temperature of 60° C., and then toluene is distilled off under reduced pressure to form a resin coating layer to obtain a carrier. rice field.

(Production of developer)
36 parts of glitter toner and 414 parts of carrier were placed in a 2-liter V blender, stirred for 20 minutes, and then sieved at 212 μm to prepare a developer.

[Developer (2)]
A binder resin was synthesized as follows.
Dimethyl fumarate: 87 parts Dimethyl terephthalate: 192 parts Bisphenol A ethylene oxide 2 mol adduct: 216 parts Bisphenol A propylene oxide 2 mol adduct: 48 parts Tetrabutoxy titanate (catalyst): 0.037 parts The above components are placed in a heat-dried two-necked flask, and the temperature is raised while maintaining an inert atmosphere by introducing nitrogen gas into the vessel and stirring, followed by cocondensation reaction at 160° C. for 7 hours, and then gradually up to 10 Torr. The temperature was raised to 220° C. while the pressure was reduced to 220° C., and the temperature was maintained for 4 hours. Once the pressure was returned to normal pressure, the pressure was gradually reduced to 10 Torr again, and the pressure was maintained at 220° C. for 1 hour to synthesize a binder resin.
Glitter Toner (2) was obtained in the same manner as Glitter Toner (1), except that the obtained binder resin was used.
A developer (2) was obtained in the same manner as the developer (1), except that the glitter toner (2) obtained was used.
The average maximum thickness C of the glitter toner particles was 1.95 μm, and the average circle equivalent diameter D of the glitter toner particles was 15.6 μm.

[Developer (3)]
A binder resin was obtained in the same manner as in the preparation of the glitter toner (1), except that dimethyl adipate: 82 parts was used instead of dimethyl fumarate: 74 parts.
A glitter toner (3) was obtained in the same manner as the glitter toner (1), except that the obtained binder resin was used.
A developer (3) was obtained in the same manner as the developer (1), except that the glitter toner (3) obtained was used.
The average maximum thickness C of the glitter toner was 1.133 μm, and the average circle equivalent diameter D of the glitter toner particles was 10.3 μm.

[Developer (4)]
Dimethyl fumarate: 82 parts was used in place of 74 parts of dimethyl adipate, the number of parts of bisphenol A propylene oxide 2 mol adduct was changed to 147 parts instead of 48 parts, and trimellitic anhydride was not used. A binder resin was obtained in the same manner as in the preparation of the glitter toner (1).
A glitter toner (4) was obtained in the same manner as the glitter toner (1), except that the obtained binder resin was used.
A developer (4) was obtained in the same manner as the developer (1), except that the glitter toner (4) obtained was used.
The average maximum thickness C of the glitter toner particles was 2.22 μm, and the average circle equivalent diameter D of the glitter toner particles was 5.4 μm.

[Developer (5)]
Dimethyl fumarate: 74 parts were replaced with dimethyl adipate: 82 parts, the number of parts of bisphenol A propylene oxide 2-mol adduct was replaced with 48 parts with 147 parts, and the number of trimellitic anhydride was replaced with 9 parts. A binder resin was obtained in the same manner as in the synthesis of the binder resin in the preparation of the glitter toner (1), except that the total amount was 12 parts.
Glitter Toner (5) was obtained in the same manner as Glitter Toner (1), except that the obtained binder resin was used. However, the viscosity at 130° C. was adjusted to the value shown in Table 1 to obtain Glittering Toner (5).
A developer (4) was obtained in the same manner as the developer (1), except that the glitter toner (5) obtained was used.
The average maximum thickness C of the glitter toner particles was 4.27 μm, and the average circle equivalent diameter D of the glitter toner particles was 8.1 μm.

<Examples 1 to 26, Comparative Examples 1 to 2>
The developer shown in Table 1 was used in the developing device for bright image formation of the image forming apparatus "Versant 3100 iPress" manufactured by Fuji Xerox Co., Ltd. (modified machine equipped with a fixing device having the same configuration as the fixing device shown in FIG. 3). filled. However, the configuration of the fixing device was set as shown in Table 1.
It should be noted that the nip configuration of the fixing device shown in Example 26 is nearly flat and slightly curved.
Then, using this image forming apparatus, the following evaluation was carried out.

(Brightness evaluation)
Using the image forming apparatus of each example, an OK top-coated paper (basis weight: 127: manufactured by Oji Paper Co., Ltd.) was coated with a glitter toner having a loading of 3.5 g/m ² and a glitter having a size of 5 cm × 5 cm. 20 solid images of color were output.
The twentieth sheet of bright solid image was irradiated with incident light at an incident angle of -45° to the solid image using a spectroscopic goniochromatic color difference meter GC5000L manufactured by Nippon Denshoku Industries Co., Ltd. as a goniophotometer. A reflectance X at an acceptance angle of +30° and a reflectance Y at an acceptance angle of -30° were measured. The reflectance X and the reflectance Y were measured at intervals of 20 nm for light with a wavelength in the range of 400 nm to 700 nm, and the reflectance at each wavelength was averaged.
A ratio (X/Y) was calculated from these measurement results and evaluated according to the following evaluation criteria.
The higher the ratio (X/Y), the higher the feeling of brightness, and the lower the ratio (X/Y), the stronger the dull feeling and the less feeling of brightness.
A: The ratio (X/Y) is 80 or more and 100 or less B: The ratio (X/Y) is 60 or more and less than 80 C: The ratio (X/Y) is 2 or more and less than 60 D: The ratio (X/Y) is less than 2

From the above results, it can be seen that the present example can form a glitter image with a high glitter feeling due to the glitter toner as compared with the comparative example.

2 Flat toner particles 4 Flat pigment L Thickness of flat toner particles 111Y, 111M, 111C, 111K, 111B Photoreceptor 113 Drive roll 112 Support roll 114 Counter rolls 115Y, 115M, 115C, 115K, 115B Cleaning device 116 Intermediate transfer belt cleaning Devices 117Y, 117M, 117C, 117K, 117B Primary transfer rolls 118Y, 118M, 118C, 118K, 118B Charging rolls 119Y, 119M, 119C, 119K, 119B Exposure devices 120Y, 120M, 120C, 120K, 120B Development device 133 Intermediate transfer belt 134 secondary transfer roll 135 fixing device 140Y, 140M, 140C, 140K, 140B toner cartridge 150Y, 150M, 150C, 150K, 150B image forming unit

Claims (12)

a developing device containing a developer having a bright toner containing a flat bright pigment, and developing an electrostatic charge image formed on a surface of an image carrier by the developer as a toner image;
A fixing device for fixing a toner image on a surface of a recording medium, comprising: a fixing belt; first and second rolls arranged inside the fixing belt to support the fixing belt while applying tension; a fixing device having a pressure roll that sandwiches the fixing belt together with a first roll to form a nip portion, and that has a fixing temperature of 130° C. or more and 230° C. or less;
a unit with 2. The unit of claim 1, wherein said nip is flat. 3. The unit according to claim 1, wherein the fixing belt is rotationally driven at a linear velocity of 180 mm/sec to 450 mm/sec. 4. The unit according to any one of claims 1 to 3, wherein a difference (absolute value) in surface hardness between said first roll and said pressure roll is within 15°. 5. The unit according to claim 4, wherein the first roll has a surface hardness of 35[deg.] or more and 45[deg.] or less. 6. The unit according to claim 4, wherein the pressure roll has a surface hardness of 40[deg.] or more and 50[deg.] or less. The unit according to any one of claims 4 to 6, wherein the pressure at the nip portion is 2.0 kgf/cm ² or more and 7.0 kgf/cm ² or less. The unit according to any one of claims 4 to 6, wherein the pressure at the nip portion is 4.0 kgf/cm ² or more and 7.0 kgf/cm ² or less. The outer diameter ratio (first roll/pressure roll) of the first roll and the pressure roll is 0.9 or more and 1.3 or less, according to any one of claims 4 to 8. unit. The unit according to any one of claims 1 to 9, wherein the glitter toner has a viscosity of 100 Pa·s or more and 1000 Pa·s or less at 130°C. The ratio (C/D) of the average maximum thickness C to the average equivalent circle diameter D of the toner particles of the glitter toner is in the range of 0.001 to 0.700. A unit according to any preceding clause. a toner image forming apparatus having an image carrier and the developing device of the unit according to any one of claims 1 to 11, and forming a toner image on the surface of the image carrier;
a transfer device for transferring the toner image formed on the surface of the image carrier onto the surface of a recording medium;
A fixing device for fixing the toner image onto the surface of the recording medium, comprising: the fixing device of the unit according to any one of claims 1 to 11;
An image forming apparatus comprising:

Images